1. Field of the Invention
The present invention relates to a fan monitoring system for electronic systems including computer systems.
2. Description of the Related Art
Electronic components, such as processors, gate arrays, programmable logic, expansion cards, memory chips, disk drive motors, and power supplies generate heat during normal operation. Because these electronic components are usually enclosed within a protective housing such a computer chassis, the heat produced by these components can be trapped within the housing, and thus, cause the temperature to rise within the housing. These high temperatures can damage the semiconductor circuits located within the protective housing or significantly shorten the working life of the electronic components. In some cases, these circuits may catastrophically fail due to the high temperatures.
One common method of reducing the temperature inside the protective housing of electronic systems is to use a fan to circulate the air inside the housing and to bring in cooler air from outside the housing. However, if the fan fails, the heat trapped inside the protective housing can quickly raise the temperature to the point of damaging the circuits. Another problem is that the fan may not be connected or installed properly, due to human error.
What is needed is a system to detect when a fan is not rotating or when a fan is not installed and to provide signals which indicate these conditions.